Boeing Model 15

The Boeing Model 15 was a single-seat, open-cockpit biplane fighter of the 1920s built by Boeing for the United States. It served with the United States Army Air Service as the PW-9 series and with the United States Navy as the carrier-based FB series. The design drew on studies of the Fokker D.VII, 142 of which were brought to the United States for evaluation after the First World War, and used a welded steel tube fuselage with fabric-covered wooden wings and streamlined steel struts. The first prototype, the XPW-9, flew on 2 June 1923, and the FB-5 first flew on 7 October 1926 and joined the Navy the following January.